Medicare Initial Enrollment Period
You have a 7-month window to sign up for Medicare when you turn 65. Miss it, and you could face a permanent penalty — and a gap in coverage.
Here is exactly when your IEP starts, how to apply, whether you are automatically enrolled, and what to do if you are still working at 65.
What Is the Medicare Initial Enrollment Period?
The Medicare Initial Enrollment Period (IEP) is the first — and most important — window you have to sign up for Medicare. It is a 7-month period centered on your 65th birthday month:
3 Months Before
Your 65th birthday month
✓ Best time to enroll
Birthday Month
The month you turn 65
Coverage delayed 1 mo.
3 Months After
Your 65th birthday month
Coverage delayed 2–3 mo.
The IEP applies to Medicare Part A (hospital insurance) and Medicare Part B (medical insurance). Once your IEP ends, you generally cannot enroll in Medicare until the General Enrollment Period (January 1 – March 31 each year), and you may face a permanent late enrollment penalty.
The 7-Month IEP Timeline — When Coverage Starts
When you enroll matters — not just whether you enroll. Here is exactly when your Medicare coverage begins based on when during your IEP you sign up:
| When You Enroll | Coverage Starts | Recommendation |
|---|---|---|
| 3 months before birthday month | First day of birthday month | ✅ Best — no gap in coverage |
| 2 months before birthday month | First day of birthday month | ✅ Good |
| 1 month before birthday month | First day of birthday month | ✅ Good |
| Birthday month (month you turn 65) | 1 month after enrollment | ⚠️ 1-month delay |
| 1 month after birthday month | 2 months after enrollment | ⚠️ 2-month delay |
| 2–3 months after birthday month | 3 months after enrollment | ⚠️ 3-month delay |
Birthday rule exception: If your birthday falls on the first day of a month, Medicare treats the prior month as your birthday month. Your IEP starts 4 months before the month you turn 65.
Are You Automatically Enrolled in Medicare at 65?
Whether you are automatically enrolled depends entirely on whether you are already receiving Social Security benefits:
Auto-Enrolled — You DO NOT Need to Apply
- • Already receiving Social Security retirement benefits
- • Already receiving Railroad Retirement Board benefits
- • Receiving Social Security disability benefits (SSDI) for 24+ months
Your Medicare card will arrive in the mail about 3 months before your 65th birthday.
Must Actively Apply — You Are NOT Auto-Enrolled
- • Not yet collecting Social Security at 65
- • Delaying Social Security to age 66, 67, or 70
- • Still working and covered by employer insurance
- • Self-employed or covered by a spouse's employer plan
You must sign up during your IEP or risk a late enrollment penalty.
This is one of the most common Medicare mistakes — people assume they will be automatically enrolled because they are turning 65, but if you are not already drawing Social Security, nothing happens automatically. You must take action.
How to Apply for Medicare Part A and Part B
Applying for Medicare is handled through the Social Security Administration (SSA) — not Medicare directly. You have three options:
Apply Online at ssa.gov/medicare
RecommendedThe fastest option. Takes about 10 minutes. Available 24/7. You will receive a confirmation number immediately.
Call Social Security at 1-800-772-1213
Phone OptionAvailable Monday–Friday, 8 a.m.–7 p.m. local time. Have your Social Security number, birth certificate, and proof of citizenship or legal residency ready.
Visit Your Local Social Security Office
In-PersonSchedule an appointment at ssa.gov/locator. Bring your Social Security card, birth certificate, and a photo ID.
What You Will Need to Apply
- Social Security number
- Date and place of birth
- Proof of U.S. citizenship or legal residency
- Current health insurance information (if any)
- Employer information (if still working)
- Bank account info (for premium auto-pay, optional)
What Happens If You Miss Your IEP?
Missing your IEP without a qualifying exception has two serious consequences:
Permanent Late Enrollment Penalty
For every 12-month period you were eligible for Part B but did not enroll, your monthly Part B premium increases by 10% permanently — for as long as you have Medicare.
Example: 2 years late = 20% higher premium for life. In 2026, the standard Part B premium is $202.90/month — a 20% penalty adds $37/month, or $444/year, forever.
Coverage Gap Until July
You must wait for the General Enrollment Period (January 1 – March 31) to sign up, and your coverage will not start until July 1 of that year.
That could mean months without Medicare coverage — and potentially no access to Medicare Advantage or Medigap plans during that gap.
Exception: Special Enrollment Period (SEP)
If you missed your IEP because you were covered by a qualifying employer health plan (through your own or your spouse's current employment), you qualify for a Special Enrollment Period. You have 8 months after that employer coverage ends to enroll in Medicare without penalty. This is the most common legitimate reason to delay Medicare past 65.
Still Working at 65? What You Need to Know
If you are still working at 65 and covered by an employer health plan, you have options — but the rules depend on the size of your employer:
| Employer Size | Medicare Is... | Recommendation |
|---|---|---|
| 20+ employees | Secondary payer | Can delay Part B — employer plan pays first. Enroll in Part A (usually free). Sign up for Part B within 8 months of leaving. |
| Under 20 employees | Primary payer | Must enroll in Medicare at 65. Small employer plans become secondary — you could face large out-of-pocket costs without Medicare. |
| Self-employed / COBRA | Primary payer | COBRA is NOT creditable coverage for Medicare purposes. Enroll during your IEP to avoid penalties. |
The employer size rule is one of the most misunderstood areas of Medicare enrollment. Getting this wrong can cost you thousands in penalties and uncovered medical bills. Talk to me before you decide — this is exactly the kind of situation where a 15-minute conversation can save you years of overpaying.
Frequently Asked Questions
Q.What is the Medicare Initial Enrollment Period?
The IEP is a 7-month window — 3 months before your 65th birthday month, the birthday month itself, and 3 months after — during which you can first sign up for Medicare Part A and Part B without a late enrollment penalty.
Q.When should I sign up for Medicare at 65?
Sign up during the 3 months before your 65th birthday month for coverage to start on the first day of your birthday month. Signing up in your birthday month or after causes a 1–3 month delay in coverage.
Q.Am I automatically enrolled in Medicare at 65?
Only if you are already receiving Social Security or Railroad Retirement Board benefits. If you are not yet collecting Social Security, you must actively sign up — nothing happens automatically.
Q.How do I apply for Medicare Part B online?
Go to ssa.gov/medicare and complete the online application. It takes about 10 minutes. You will need your Social Security number, date of birth, and current insurance information.
Q.What is the Medicare enrollment deadline when turning 65?
Your IEP ends 3 months after your 65th birthday month. After that, you must wait for the General Enrollment Period (January 1 – March 31) and face a potential late enrollment penalty.
Q.Can I delay Medicare if I have employer insurance?
Yes — if you are covered by a qualifying employer plan through your own or your spouse's current employment at a company with 20 or more employees, you can delay Part B without penalty. You have 8 months after that coverage ends to enroll.
Q.Does Medicare Part A cost anything?
Most people get Medicare Part A for free if they or their spouse paid Medicare taxes for at least 10 years (40 quarters). If you do not qualify for premium-free Part A, you can buy it — but this is uncommon.
Not Sure When Your IEP Starts?
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Related Medicare Guides
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